Ce and Yb doped InP layers grown for radiation detection

InP single crystals were grown by liquid phase epitaxy on semi‐insulating InP:Fe substrate with cerium (Ce) and ytterbium (Yb) additions to the growth melt. Grown layers were characterised by Hall measurements and low temperature photoluminescence spectroscopy. Both types of layers exhibit the change of electrical conductivity from n to p type. Ce and Yb have been found to be incorporated into the InP lattice since a sharp luminescence lines arising from inner shell transitions of Yb3+ and Ce3+ were detected at 1002 and 3534 nm, respectively. A metastable conductivity state of InP:Ce layers has been found at temperatures below 35 K, a phenomenon previously reported for InP:Yb layers. Similar electrical behaviour of InP (Ce, Yb) layers leads us to conclude that Ce acts as dominant acceptor impurity responsible for n→p conductivity change. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)